Take the west gate in Cyseal (just north of the General Store).
Head northeast. You'll find a burning chest, just to the east of that there's a clearing with a bunch of skeletons and some boars. At the back of the clearing is a cave.
There's another quest inside the cave but if you follow it around to the back you find an opening to a river.
Follow the river westwards and you'll find a Waypoint, and if you go down from there you reach the beach where, amoung other things, you'll find the entrance to Evelyn's lair.
Hope that helps!
